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| Titel |
ELF wave generation in the ionosphere using pulse modulated HF heating: initial tests of a technique for increasing ELF wave generation efficiency |
| VerfasserIn |
R. Barr, P. Stubbe, M. T. Rietveld |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 17, no. 6 ; Nr. 17, no. 6, S.759-769 |
| Datensatznummer |
250013774
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| Publikation (Nr.) |
 copernicus.org/angeo-17-759-1999.pdf |
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| Zusammenfassung |
This paper describes the results of a
preliminary study to determine the effective heating and cooling time constants
of ionospheric currents in a simulated modulated HF heating, `beam painting'
configuration. It has been found that even and odd harmonics of the fundamental
ELF wave used to amplitude modulate the HF heater are sourced from different
regions of the ionosphere which support significantly different heating and
cooling time constants. The fundamental frequency and its odd harmonics are
sourced in a region of the ionosphere where the heating and cooling time
constants are about equal. The even harmonics on the other hand are sourced from
regions of the ionosphere characterised by ratios of cooling to heating time
constant greater than ten. It is thought that the even harmonics are sourced in
the lower ionosphere (around 65 km) where the currents are much smaller than at
the higher altitudes around 78 km where the currents at the fundamental
frequency and odd harmonics maximise.
Key words. Electromagnetics (antennae) · Ionosphere
(active experiments) · Radio science (non linear phenomena) |
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